From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2BB443932FA for ; Wed, 3 Jun 2026 23:26:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780529184; cv=none; b=bhpGUQG7HTS2SFVRu1SuhS0j+nOk6+NbCvQnXbzgT3w7H7lpObyusJHO3Avk2Gq37h2nMCxHj70yhKmq98TPhEXWSuc18YuiHhrs4o6BpwRUp78P61+ZgTuf05mdtwq0mqUcXGPP6ZlXAd8A7QzivtiM498E0AdsOZTyGMlWC4U= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780529184; c=relaxed/simple; bh=AokCZUPnucU/Ii3/5XIu6GVPxnB4+GY7tXZe31HNaWI=; h=Date:To:From:Subject:Message-Id; b=h8T2yQwx0HGGyX2BnCYlYCyJHnpHxTd30vze1WPd5s1eOeBuV9jDyLT3vNCeOz5PiwR+XKel3nmVbw/FhhDIxKnIsBgAccyRbiExkZNMiLGfwEKTHdbxwaTPPnzD8L2Dk3fYlZcKS85xK/fdSqwU/be4YIXiE4o/aVRLMkjgl+o= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=ShawkhHr; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="ShawkhHr" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DDD601F00898; Wed, 3 Jun 2026 23:26:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=korg; t=1780529183; bh=7IeZzmxJ3F+nWheH3j3kpn8EDlOBnP7Olo5x9frOAJA=; h=Date:To:From:Subject; b=ShawkhHrJ6fzhwrMIhE2HUSIEDAcwiKyeaw9my1BAvLibx8r1Bwr+CMcCCXKlhRZ1 j14YTnNLQTZY0Gts49I+NoKqKKOMUfIhlFSmhc+FfaW2X6AQ/MM5gE0uN8RS5dAUJL wpLhS1slO6xu8sy8/GQlSA4N8fZcHME8+m18O9Ug= Date: Wed, 03 Jun 2026 16:26:22 -0700 To: mm-commits@vger.kernel.org,vbabka@kernel.org,surenb@google.com,songmuchun@bytedance.com,rppt@kernel.org,muchun.song@linux.dev,minchan@kernel.org,mhocko@suse.com,ljs@kernel.org,liam@infradead.org,jhubbard@nvidia.com,gregkh@linuxfoundation.org,digetx@gmail.com,david@kernel.org,chengkaitao@kylinos.cn,akpm@linux-foundation.org From: Andrew Morton Subject: [merged mm-hotfixes-stable] mm-cma_sysfs-skip-inactive-cma-areas-in-sysfs.patch removed from -mm tree Message-Id: <20260603232622.DDD601F00898@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The quilt patch titled Subject: mm/cma_sysfs: skip inactive CMA areas in sysfs has been removed from the -mm tree. Its filename was mm-cma_sysfs-skip-inactive-cma-areas-in-sysfs.patch This patch was dropped because it was merged into the mm-hotfixes-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Kaitao Cheng Subject: mm/cma_sysfs: skip inactive CMA areas in sysfs Date: Fri, 22 May 2026 21:14:34 +0800 cma_activate_area() can fail after a CMA area has already been added to cma_areas[]. In that case the area is left in the global array, but it does not reach the point where CMA_ACTIVATED is set. cma_sysfs_init() currently walks all cma_area_count entries and creates sysfs files for every area, including ones that failed activation. These areas are not usable CMA areas and should not be exposed to userspace as valid CMA regions. If such an inactive area is exposed, userspace sees a CMA directory whose read-only accounting files report zeros. total_pages and available_pages report zero because the failed activation path clears cma->count and cma->available_count, while the allocation and release counters also stay at zero because the area cannot service CMA allocations. This makes the failed area look like a valid but empty CMA region and can mislead tests, monitoring, and diagnostics. Skip CMA areas that did not reach CMA_ACTIVATED when creating the sysfs objects. Since inactive entries can now be skipped, make the error unwind tolerate entries that never had cma_kobj initialized. Link: https://lore.kernel.org/20260524140420.61864-1-kaitao.cheng@linux.dev Link: https://lore.kernel.org/20260522131434.78532-1-kaitao.cheng@linux.dev Fixes: 43ca106fa8ec ("mm: cma: support sysfs") Signed-off-by: Kaitao Cheng Reported-by: David Hildenbrand (Arm) Suggested-by: David Hildenbrand (Arm) Suggested-by: Muchun Song Reported-by: Muchun Song Closes: https://lore.kernel.org/linux-mm/55481a8b-dcfc-4bef-ba59-aa0b43dca88b@kernel.org/ Acked-by: Muchun Song Cc: David Hildenbrand Cc: Dmitry Osipenko Cc: Greg Kroah-Hartman Cc: John Hubbard Cc: Liam R. Howlett Cc: Lorenzo Stoakes Cc: Michal Hocko Cc: Mike Rapoport Cc: Minchan Kim Cc: Suren Baghdasaryan Cc: Vlastimil Babka Signed-off-by: Andrew Morton --- mm/cma_sysfs.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) --- a/mm/cma_sysfs.c~mm-cma_sysfs-skip-inactive-cma-areas-in-sysfs +++ a/mm/cma_sysfs.c @@ -117,13 +117,16 @@ static int __init cma_sysfs_init(void) return -ENOMEM; for (i = 0; i < cma_area_count; i++) { + cma = &cma_areas[i]; + if (!test_bit(CMA_ACTIVATED, &cma->flags)) + continue; + cma_kobj = kzalloc_obj(*cma_kobj); if (!cma_kobj) { err = -ENOMEM; goto out; } - cma = &cma_areas[i]; cma->cma_kobj = cma_kobj; cma_kobj->cma = cma; err = kobject_init_and_add(&cma_kobj->kobj, &cma_ktype, @@ -138,7 +141,8 @@ static int __init cma_sysfs_init(void) out: while (--i >= 0) { cma = &cma_areas[i]; - kobject_put(&cma->cma_kobj->kobj); + if (cma->cma_kobj) + kobject_put(&cma->cma_kobj->kobj); } kobject_put(cma_kobj_root); _ Patches currently in -mm which might be from chengkaitao@kylinos.cn are mm-page_isolation-avoid-unsafe-folio-reads-while-scanning-compound-pages.patch